Device for automatically exchanging



1956 H. SGHUMANN ET AL DEVICE FOR AUTOMATICALLY EXCHANGING BOBBINS ON SEWING MACHINES 4 Sheets s t 1 Filed- Aug. 6, 1952 &

mes IVE/F6567 Joya/mm H. SCHUMANN ET AL DEVICE FOR AUTOMATICALLY EXCHANGING BOBBINS 0N SEWING MACHINES Feb. 7, 1956 Filed Aug. 6, 1952 4 Sheets-Sheet 2 INV'A/I'OPS #595097 sow/MAW Feb. 7, 1956 H. SCHUMANN ET AL 2,733,676

DEVICE FOR AUTOMATICALLY EXCHANGING BOBBINS ON SEWING MACHINES Filed Aug. 6, 1952 4 Sheets-Sheet 3 INVA'NMIRS #096697 50/0/1440 [Ar/4 Cd 4 (4525 Feb. 7, 1956 H SCHUMANN ET AL 2,733,676

DEVICE F OR AUTONMTI CALLY EXCHANGING BOBBINS ON SEWING MACHINES Filed Aug. 6, 1952 4 Sheets-Sheet 4 United States Patent DEVICE FOR AUTOMATICALLY EXEHANGING BOBBENS 0N SEWING MACHINES Herbert Schumann and Emil Clauss, Kaiserslautern (Pfalzz), Germany, assiguors to G. M. Pfaif A. G., Kaisersiautern (Pfalz), Germany Application August 6, 1952, Serial No. 362.3%

8 Claims. (Cl. 112-180) In sewing machines the exchanging of bobbins is effected in such a manner that the shuttle with the coil is removed from the loop catch or loop-taker, a wound bobbin is placed in the shuttle and then the shuttle is set.into the loop catch or loop taker. These operations are cumbersome and time consuming.

Also a mechanical way of exchanging bobbins has been known for some time. For example, in connection with sewing machines operating with elongated shuttles it has been proposed to exchange the bobbins by means of a rotary carrier in the form of a disk having a multicornered member movable in the direction of the bobbin, which introduces a new shuttle in the operating area at the proper time.

The bobbins here must also be removed manually from the rotary carrier and placed into it manually. Thus it is only achieved that the exchange while it may be effected in a certain order and at certain time intervals may only be undertaken to a limited extent in accordance with the limited number of the bobbins or shuttles provided upon the rotary carrier.

It is furthermore known to mechanically expel empty bobbins out of the bobbin housing. For that purpose two pusher rods connected by a hand lever are employed. One of the pusher rods here has merely the task of making the shuttle accessible by opening a sliding memher to perform the bobbin exchange which takes place manually.

For these and all other proposals based on similar considerations the mechanical bobbin exchange cannot succeed in actual practice because it is not possible to insert the thread of the wound bobbin mechanically into the shuttle. Thus, most inventors were satisfied to merely expel the empty bobbin.

One proposal is known which deals with this shortcoming where the bobbin exchange is effected mechanically in that the empty bobbin together with the shuttle is automatically expelled from the seat in the loop catch by operating a shifting member and is replaced by a filled bobbin and a shuttle from a magazine. In this known arrangement the shifting member is in the form of a piston which is displaceable by means of a rod in a tubular magazine which is capable of accommodating a limited number of bobbinand shuttle units. At the operating knob of the piston rod which is disposed at .the' opposite end of the tubular magazine the rotary shuttle or the loop catch is disposed in axial alignment which has a receptacle for the bobbin and an insert aperture for a shuttle with a filled bobbin facing in the direc- 'llOH of the magazine. The shuttle with the empty bobbin is expelled from the loop catch in an axial direction through the exit aperture and is replaced in that shuttle when a full bobbin is pushed into the housing of the loop catch by means of the magazine piston and in the process removes the shuttle with'the empty bobbin. In this connectionthe first bobbin must be moved back correspondingly in the magazine. Each shuttle unit requires a separate base plate, separate guide grooves for the thread and a retaining finger which in conjunction with other measures prevents rotation of the shuttle. The magazine must be provided with a guide groove. For pressing a filled shuttle into the loop catch the shuttle must first be placed in a predetermined position in the magazine. Also this is a necessary condition for the subsequent advancing of the shuttle.

With the prior proposal the fact that the conventional loop catch cannot be used and that the loop catch requires special retaining, supporting and operating means depending upon the shuttles being pushed through, is a particular handicap.-

The invention'provides a practically useful solution of the problem of the automatic exchange of the bobbin with the shuttle by using simple means and by deliberately avoiding special conformations of the loop catch as well as supporting and operatingmeans of the same. Also the conventional form of construction of the loop catch, driving means and shuttle can be retained either with or without a few minor changes. It is even possible by means of the invention to adapt existing sewing machines for mechanical bobbin exchange subsequently without reconstruction.

The new procedure in accordance with the invention resides primarily in the feature that the empty bobbin with shuttle is seized by a grip claw carrier disposed axially parallel to the loop catch and which executes a combination of axial and pivotal movements, is lifted from the seat in the loop catch and subsequently dropped during the pivotal movement of the grip claw carrier, While at the same time a shuttle with a full bobbin is picked up from the magazine and deposited in the seat in the loop carrier.

In addition to the aforementioned advantages such a procedure permits the use of magazines having a large number of shuttles with filled bobbins.

in accordance with a further feature of the invention it is possible for the switching member by means of two gripping claws to simultaneously pick up the shuttle with an empty bobbin and one with a filled bobbin and by automatic return movement of the grip claw carrier to raise them from their seats and by a subsequent pivotal movement to scrape off the shuttle with the empty bobbin by means of a scraper into a collection box and to introduce the shuttle with the full bobbin in the seating position in front of the loop catch. At the same time a new movement of the switching member deposits the shuttle with the full bobbin in the seat of the loop catch and releases it from the grip claw by means of a special depositing member while the other grip claw efiects an idle movement. l

It is also possible to proceed in a manner that for a single operation of the switching member or control lever for the grip claw carrier a guide curve or the like is provided in such a manner that it transfers the necessary impulses by a continuous movement, i. e. two axial displacements and one rotation to the shaft of the grip claw carrier.

Further characteristicsof the invention and details of the advantages derived therefrom will be understood by referring to the following specification and the illustration of the various operating conditions of' the embodiment shown by the drawings in which:

Fig. 1 shows perspectively from the bottom a sewing machine which is suitable for carrying out the new process, ready for operation with the parts which are of interest in inoperative position;

Fig. 2 illustrates the gripping of the empty bobbin with shuttle while a shuttle with a full bobbin has been removed by the other grip claw from a feeding device which is not shown in a manner not obtainable from this illustration but described later; i

in the embodiment shown on] Fig. 2a is a detail view of the mechanism with the ratchet gear exposed;

Fig. 3 shows the removed shuttle with the empty bobbin while it must be assumed that the second grip claw carries a second shuttle picked up from the feeding device;

Fig. 4 shows an intermediate position of the grip claw carrier, the so-called dropping position where the shuttle With the empty bobbin is dropped into a collection box,

Fig. 5 is an enlarged view of the gripping claw illustrated in Figs. 1 to 4 and showing the grip claw fork engaged with a pin of the shuttle hinge and the spring of the gripping claw engaging the nose of the shuttle;

Fig. 6 is a view of the gripping claw illustrated in Fig. 5 in the shuttle engaged position; and

Fig. 7 is a view partially in section illustrating the pin and the cooperating groove of the shifting shaft arrangement for imparting rotational movement to the grip claw carrier arm.

Underneath the front side of the base plate 1 of the sewing machine the carrier 2 for the device in accordance with the invention is secured which carries the shifting shaft 4 in the bearing 3 while the other end of the shaft is carried by the cooperating bearing 5 in the mounting plate 6. The shifting gear 7' is disposed upon the shaft 4 the return movement of which is prevented by the spring blade 8 by way of a pin '9 and serrations or teeth 7a which are provided upon the side of gear 7 which faces the bearing 3.

The grip claw carrier arm 10 having gripping claws 11 and 12 is provided upon the shaft 4 and is pressed against the curved track 14 on the shifting lever or operating member 15 of a dual purpose actuating means. Inside of the cylindrical sleeve or hub of the grip claw carrier 10 as shown in Fig. 7 is a pin 32 which has sliding engagement with a groove 33 in the shaft 4. This pin 32 imparts rotational movement to the grip claw carrier 10. A sleeve element 'may be loosely mounted on shaft 4 between carrier '10 and shifting rod 15.

The grip claw carrier 10 is provided with two bores 16 and 1.7 as a further insurance against turning while in operative position into which bores enters the stop pin 18 which is secured to mounting plate 6. The shifting lever 15 slides in the bearing 19 of the carrier 2 and encompasses the shaft 4 with the slot in its forward end. A curve track 14 is provided at the bottom side of the shifting lever 15. The return movement of the shifting lever 15 to the starting position by 'means of a spring which is not shown, is transferred to the gear 7 by a gear rack 20 pivotally secured to the shifting lever 15 by a pin 20a which is pressed against the gear 7 by a spring blade which is not shown. At the front end of the shifting lever 15 an operating knob 21 is provided.

The grip claws 11 and 12 are pivotally mounted on the grip claw carrier 10 in the bearing 22. At the front end each carries a claw element 23 and a spring 24 and at the back end a fork element 25. Each claw element 23, as shown in Figs. 5 and 6, is provided with fingers which grasp the sliding member 29 on the sides thereof during a shuttle engaging operation. Spring 24 which partially surrounds the claw element 23 is in the form of a claw finger which engages one end ofsliding member 29. The grip claws are prevented from pendulum movements by the springs 26 secured to the grip claw carrier 19 and the shuttle 27 is grasped by the grip claw fork at the pin 28 and by the claw 23 at the front end of the sliding mernber 29 and is retained by the spring 24. The front end of the sliding member 29 is provided with a nose which is grasped by claw element 23 on the sides thereof as spring 24 slides over and under the end of the nose. The P111 28 is'the customary pin of the shuttle hinge of'which y the hinge flap has been removed while the slide with the leaf like hinge bearings and the pin journalled therein are retained.

The bobbin exchange takes place as follows:

On pressing inwardly on the push button 21 the grip claw carrier 10 is moved downwardly by the curve-track 14- against the pressure of spring 13. The grip claw grasps the shuttle 27 which is in the machine together with its empty bobbin while the other grip claw simultaneously picks up a shuttle with a full bobbin which is fed by a magazine or any other means not shown.

During the return movement of the shifting lever 15 into the starting position which is efiected under the pressure of a spring which is not shown, the grip claw carrier 10 moves axially under the effect of a pressure spring 13 and upwardly according to the illustration and lifts both shuttles i. e. the one disposed in the machine with the empty bobbin and that presented from a magazine or the like with its full bobbin.

Subsequently the turning movement of the grip claw carrier 10 takes place by way of the toothed rack 29 and the gear 7. During this operation the shuttle with the empty bobbin lifted out of the loop catch is scraped off by a scraping device not shown into a collection device and the shuttle with the full bobbin which is simultane ously picked up is brought into the insert position in front of the loop catch or loop-taker.

By means of a second operation of the push button 21 the shuttle with the full bobbin is set into the loop catch and released from the grip claw by a release means not shown, while the first grip claw simultaneously makes an idle movement. This operation is then repeated for the next bobbin exchange.

in the embodiment described and illustrated in the appended drawings it is assumed that the shuttle with the empty bobbin is lifted mechanically out of its operating position in the loop catch and turned and dropped while simultaneously a shuttle with a full bobbin is gripped and placed before the loop catch.

In the illustrated embodiment a two step operation of the operating knob 21 which carries the shifting lever 15 is required for eifecting the various operations. However, it is also possible to so construct the device that instead of operating the shifting lever 15 twice as mentioned above only a single shifting impulse is applied to the operating member such as the operating lever. For that purpose a guide curve can be provided in accordance with known auxiliary means in such a manner that the required impulses are transferred to the control shaft in a single progressive movement.

In accordance with the invention it is of no significance whether the operation of the device for the purpose of lifting up the shuttle with the empty bobbin and the inserting of a new shuttle with a new bobbin by hand is controlled with the foot, with the knee, or in any other manner. Also the places of the sewing machine where the operating means are mounted can be chosen as desired. Thus control means are possible using a pressure knob to the operation of which an electromagnet responds. Also hydraulic and other control devices should be considered.

The invention is not to be limited to the use of the construction of the grip claws shown in the illustrated embodiment.

The illustrated gripping device is based on the combination of the claw 23, the spring 24 and the fork 25. However, grip devices are possible which are differently constructed, thus the grip device may consist of one or two fixed and one movable wedge shaped rods which operate in such a manner that one or both fixed rods are introduced in the corresponding bores of the shuttle while the movable wedge shaped secondrod moves the slide of the shuttle in opposite direction to the effectiveness of the slide spring. Upon release for operation the movable rod then permits the. gripper to drop the shuttle or the scraping in the process of sealing the shuttle in the loop cat In the embodiment shown the customary flap of the ampere shuttle hinges "is eliminated. Moreover the invention is not limited to a special form of construction of the shuttle. The catching and collecting box for the shuttle with the empty bobbins can be constructed in various ways.

7 In general a container having yielding walls will be used for receiving the shuttles with the empty bobbins. If particularly correct discardingis important, arrangements can be made where the shuttles with the empty bobbins are transferred in a predetermined order into a receiving or collecting box.

The invention also provides possibility to undertake the exchange of the thread without the bobbin which is in the machine being empty. That may be desirable if it is necessary to change the color or strength of the bottom thread. For this purpose the bottom thread only need be cut off and then the device is operated which effects the bobbin exchange. Such a procedure provides a great advantage by considerable time saving in industrial establishments where numerous machines with a great variety of colors, strengths and thread thicknesses are used.

'with the full bobbins are taken a considerable number of possibilities are also provided by the invention.

The container (magazine) for the shuttle can be made in the form of a cartridge. In this cartridge the shuttles with the full bobbins are automatically placed in the discharge position under the pressure of a spring or by means of a device operated by a weight. Care must be taken that of those shuttles which are disposed inthe cartridge, that which is foremost, in readiness to be used, is freed from the discharge forces acting on it at the moment it is gripped by the grip claws.

In place of the magazine in the form of a cartridge also other arrangements for storing and feeding a plurality of filled shuttles can be used, for example slides, rotary receiving devices and the like. i

In the construction of the devices effecting the deposit and/or scraping of which one discards the shuttles with the empty bobbin from the grip claw and the other yields the shuttle with the full bobbin after insertion in the loop catch, structural changes of different types are likewise possible. In the embodiment shown the shuttle with the empty bobbins in the position of Fig. 4 is intended to be scraped off by a simple abutment which makes inefiective the spring 24. The releasing of the shuttle with the filled bobbin out of the grip claw upon insertion in the loop catch may likewise take place by a second guiding scraper or also by the movement of a spring following the grip claw carrier. This spring could, for

example, be provided on a tilting lever journalled in the;

grip claw carrier.

The arrangement in accordance with the invention may be rigidly built into the sewing machine or it may also be constructed in the form of an attachment device.

We claim:

1. A sewing machine comprising a loop-taker, a first shuttle having a bobbin mounted therein arranged adjacent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a carrier arm mounted on said shaft for rotation therewith and arranged for longitudinal movement thereof, gripping claws mounted on each end of said arm, and dual purpose means for rotating said shaft and said arm and for actuating said arm longitudinally of said shaft, said claws upon movement of said arm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing said second shuttle in said loop-taker.

2. A sewing machine comprising a loop-taker, a first shuttle having a bobbin mounted therein arranged adja cent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a carrier arm mounted on said shaft transversely thereof for rotation therewith and mountedfor longitudinal move ment thereof, gripping claws mounted on each end of said arm, and dual purpose means for. rotating said shaft and said arm and for actuating said arm longitudinally of said shaft comprising an operating member movable transversely of said shaft upon actuation of said dual purpose means and providing a curved track in sliding engagement with said arm, said operating member upon actualtion of said dual purpose means sliding over said arm transversely thereof to actuate said arm longitudinally of said shaft and imparting rotary movement to said shaft, and said claws upon movement of said arm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing said second shuttle in said loop-taker.

3. A sewing machine comprising a loop-taker, a first shuttle having a bobbin mounted therein arranged adjacent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a ratchet gear fixedly mountedon said shaft, a carrier arm mounted on said shaft transversely thereof for rotation therewith and mounted for longitudinal movement thereof, said arm comprising a sleeve element surrounding said shaft, gripping claws mounted on each end of said arm, and dual purpose means for rotating said shaft and said arm and for actuating said arm longitudinally of said shaft comprising a toothed rack in engagement with said ratchet gear and adapted to impart rotary movement to said shaft and said arm upon actuation of said dual purpose means and an operating member movable transversely of said shaft upon actuation of said dual purpose means and defining-a curved track in sliding engagement with said sleeve element, said operating member upon actuation of said dual purpose means sliding over said sleeve element transversely thereof to actuate said arm longitudinally of said shaft and said claws upon movement of said arm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing said second shuttle in said loop-taker. v

4. A sewing machine comprising aloop-takerfl: afirst shuttle having a bobbin mounted therein arranged adjacent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a mounting plate arranged at one edge of said shaft, a ratchet gear fixedly mounted on the other end of said shaft, a carrier arm mounted on said shaft transversely thereof for rotation therewith and mounted for longitudinal movement thereof, gripping claws mounted on each end of said arm, a sleeve mounted on said shaft between said arm and said ratchet gear, dual purpose means. for rotating said shaft and said arm and for actuating said arm longitudinally of said shaft comprising a toothed rack in engagement with said ratchet gear and adapted to impart rotary movement to said shaft and said arm upon actuation of said dual purpose means and an operating thereof to actuate said arm longitudinally of said shaft against the'biasing action of said spring means and said claws upon movement of saidrarm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing said second shuttle in said loop-taker.

5. A sewing machine comprising a loop-taker, a first shuttle having a bobbin mounted therein arranged adjacent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a mounting place arranged at one end of said shaft, a ratchet gear fixedly mounted on the other end of said shaft, said ratchet gear being provided with a serrated side, a spring biased pin mounted on the machine for restricting the movement of said ratchet gear and said shaft in one direction, a carrier arm mounted on said shaft transversely thereof for rotation therewith and mounted for longitudinal movement thereof, gripping claws mounted on each end of said arm, a sleeve mounted on said shaft between said arm and said ratchet gear, dual purpose means for rotating said shaft and said arm in the other direction and for actuating said armrlongitudinally of said shaft comprising a toothed rack in engagement wtih said ratchet gear and adapted to impart rotary movement to said shaft and said arm in said other direction upon actuation of said dual purpose means and an operating member movable transversely of said shaft upon actuation of said dual purpose meansand defining a curved track in sliding engagement with said sleeve, and spring means disposed on said shaft between said mounting plate and said arm for biasing said arm toward said operating member, 'said operating member upon actuation of said dual purpose means in one direction sliding over said sleeve transversely thereof to actuate said arm longitudinally of said shaft against the biasing action of said spring means and said claws upon movement of said arm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing I 7. The combination set forth 'inc'laim 5 in further combination with a stop pin mounted on said mounting plate and extending toward said arm in parallel relationship to said shaft, and said arm defining a plurality of apertures which alternately engage said stop pin upon actuation of said operating member.

8. A sewingmachine comprising a loop-taker, a first shuttle having a bobbin mounted therein arranged adjacent said loop-taker, a second shuttle having a bobbin mounted therein, and means for automatically removing said first shuttle from said loop-taker and replacing it with said second shuttle, said automatic removing means comprising a shaft rotatably mounted on the machine, a mounting plate arranged at one end of said shaft, a ratchet gear fixedly mounted on the other end of said shaft, a carrier arm mounted on said shaft transversely thereof for rotation therewith and mounted for longitudinal movement thereof, gripping claws mounted on each end of said arm, said gripping claws comprising a forked element and a spring biased claw element, a sleeve mounted on said shaft between said arm and said ratchet gear, dual purpose means for rotating said shaft and said arm and for actuating said arm lonQ'tudinally of said shaft comprising a toothed rack in engagement with said ratchet gear and adapted to impart rotary movement to said shaft and said arm upon actuation of said dual purpose means and an operating member movable transversely of said shaft upon actuation of said dual purpose means and defining a curved track in sliding engagement with said sleeve, said operating member upon actuation of said dual purpose means sliding over said sleeve transversely thereof to actuate said arm longitudinally of said shaft against the biasing action of said spring means and said claw and forked elements upon movement of said arm longitudinally of said shaft gripping said first and second shuttles and upon rotation with said shaft removing said first shuttle from said loop-taker and placing said second shuttle in said loop-taker.

References Cited in the file of this patent UNITED STATES PATENTS 906,987 Angus Dec. 15, 1908 2,298,871 Cumfer Oct. 13, 1942 2,507,470 Hirsch May 9, 1950 FOREIGN PATENTS 103,031 Austria Apr. 10, 1926 

